Numerous studies that have evaluated effects of excessive body weight on mortality suggest that mortality increases with increasing weight. The mortality ratio (the actual number of deaths as a percent of expected deaths for a population) increases with degree and duration of obesity from 110 among persons 5 to 15 percent overweight to 227 among those 55 to 65 percent overweight. Morbid obesity (100 percent over desirable weight) has been associated with a mortality ratio of 1200.
Relative body weights above 100 to 109 percent of desirable weight are associated with increased incidence of morbidity from cardiovascular diseases, cancer, diabetes, and digestive diseases. The greater the relative weight, the greater the risk for these conditions. Many other potentially serious conditions such as sleep apnea, gallbladder disease, osteoarthritis, and other bone and joint disorders are associated with obesity. In the United States alone, studies have shown that over 34,000,000 individuals could be classified as being overweight.
Weight loss and subsequent weight maintenance reduce the health risks associated with obesity. A variety of approaches including reducing caloric intake, exercise, behavior modification, drug therapy, surgery, and combinations of these methods are currently practiced. Some approaches are more "aggressive" than others.
An "aggressive" approach to weight management is not new. Prolonged total fasting under hospital supervision became an accepted approach for treating morbid obesity in the early 1960's. Total fasting (starvation) is characterized physiologically by decreases in serum insulin and glucose concentrations and increases in serum free fatty acids (from body fat) and ketone concentrations (substrate from body fat).
Additionally, total fasting results in the excretion of higher than normal concentrations of potassium (with related electrolyte imbalances) and loss of lean body mass (i.e., nitrogen--protein--losses from skeletal muscle and organ tissue). The increase in serum ketones occurring during fasting is important in decreasing body protein losses as the ketones substitute for protein-derived glucose. Although body protein losses are reduced, they remain significant and seriously detrimental. While weight loss and rate of weight loss was significant with total fasting regimens, health- and life-threatening physiologic complications such as significant loss of lean body mass, electrolyte imbalances, and nutrient deficiencies associated with this treatment limited their use.
Information obtained from early experiences with total fasting led to the development of safer and more effective dietary regimens such as the protein-sparing diet of the very-low-calorie type, (PSD/VLC), also referred to as a protein-sparing modified fast. Currently, this relatively "aggressive" approach to weight loss and management is considered an accepted treatment for obesity when used as part of a medically supervised, comprehensive program.
The goal of a PSD/VLC diet is to achieve weight loss of body fat comparable to that of fasting, while sparing lean body mass and avoiding electrolyte imbalances and nutrient deficiencies. The administration of exogenous protein (i.e., from diet) of high quality promotes improved body protein-sparing over fasting alone. Studies suggest that providing a level of protein of 1.2 to 1.5 g/kg body weight facilitates protein-sparing, thus making the PSD/VLC diet a safer regimen. PSD/VLC regimens, therefore, must contain relatively high levels of protein and very low levels of carbohydrate when compared with a "typical" diet to be safe and efficacious.
The recommended percent distribution of total calories provided by protein, fat, and carbohydrate for a "typical" diet is 15 to 20%, less than 30%, and 50 to 55%, respectively. In a "typical" diet providing as few as 800 calories (a number representative of a very-low-calorie diet), 50 to 55% of the calories as carbohydrate is approximately 100 to 110 grams. The maximum amount of carbohydrate per day that will facilitate ketone production is 50 grams. Therefore, low levels of carbohydrate (less than 50 grams per day) and high levels of protein are essential to the effectiveness of a PSD/VLC diet as they facilitate body fat utilization for energy (ketosis and free fatty acid production) and spare body protein.
PSD/VLC type diets must also provide vitamins and minerals, especially electrolytes, at levels that meet an individual's needs for maintaining nutritional status, as well as the increased needs resulting from the physiologic response to the fasting regimen. Ideally, all nutrients needed for nutritional safety should be contained in the meal replacement product to reduce the need for vitamin/mineral/electrolyte supplementation and the inherent risk of non-compliance with supplementation regimens.
Typically, individuals who respond favorably to a PSD/VLC diet may be kept on the regimen until their goal weight is obtained. Therefore, they may be on the regimen for months, usually more than 3 months and sometimes over a year. While most PSD/VLC beverages are well-tolerated, individuals often complain that they miss the action and associated sensations of chewing food while on the diet regimen. Currently, no solid food form is available that meets accepted formulation criteria for such a regimen. There is provided by the present invention a solid food form (bar) that may replace a serving of the beverage due to its similar nutritional profile. The development of a bar acceptable from organoleptic and textural properties was a challenge due to the unique nutritional profile of a bar required to accommodate the physiologic response to the PSD/VLC regimen and to make this product safe for use with such a diet regimen.
In any attempt to produce a meal replacement bar for use in conjunction with a PSD/VLC diet, it is necessary to overcome a number of inter-related problems. First, the bar must be of a palatable texture. This problem is particularly acute in attempting to design a low carbohydrate, high protein, nutrient-dense, solid food product since the high concentration of protein tends to facilitate tight bonding, such that the food product becomes rubbery or brick-like in as little as a few days. Thus, prior attempts have had problems creating a solid food product which had a reasonable shelf life with respect to a palatable texture.
The second problem, and one which has applications far beyond the creation of a high protein solid food product, is the inherent problem of flavor system having stability in high protein, low carbohydrate solid products. There are two sources to this problem, and the fact that these two sources are interrelated exacerbates the problem. The first source is the fact that carbohydrates and, to a far greater degree, proteins are known to bind flavors. Furthermore, the high level of protein present in PSD/VLC foods increases any tendency for the protein to react with the flavoring components. This problem is compounded further by the need to compensate for undesirable flavors introduced by vitamins and minerals in concentrations required by this dietary regimen.
The second source of the problem is the desired presence of the sweetener, aspartame. Aspartame is well known for reacting with flavors. The problem caused by the high level of proteins and the presence of aspartame in a PSD/VLC food product normally culminates in one of two results. The first is a food product which over time experiences a change in flavor, such that the taste becomes one which is totally undesirable. The other possible result is for the reaction of the protein and aspartame with the flavor component to cause a significant loss in flavor over a relatively short period of time. Additionally, it is extremely difficult to predict how various proteins, aspartame and flavoring components will react in a given food product.
Although problems related to the obtaining of a palatable texture and a stable flavor are the primary concerns in manufacturing such a food product, it also must be kept in mind that problems can exist in the initial selection of a flavoring component. Regardless of the theoretical stability of flavoring, any given flavor may initially react differently with a food product composition. Therefore, just because a flavoring component has been successfully used before or in conjunction with a certain food product formulation is no guarantee that the flavor will respond similarly with a different list of ingredients. There is a fair amount of prior art related to the solving of this or a similar problem. Perhaps the most pertinent are U.S. Pat. No. 4,900,566 for a confectionery product and process for producing the same; Patent WO 92/02149 for a reduced-calorie low-moisture absorbing bulking agent compositions and methods for preparing same; and Japanese Patent No. Hei 4-158744-A for a low-calorie chocolate preparation.
The U.S. Patent concerns a process and confectionery product wherein the proteinaceous material and carbohydrate material are present in a relative ratio of from about 1:1 to 1:10. In addition, the sweetening agents do not include aspartame. The patent on bulking agent compositions pertains to products which can be incorporated into chewing gum or confections similar to nougat. The Japanese patent pertains to a low-calorie chocolate preparation involving dough, however no mention is made of protein content, suitability of use in a PSD/VLC, or manufacture in food bar form.
It is thus apparent that a need exists for a solid food product such as a food bar, which provides a high level of protein, a low level of carbohydrates and is nutrient-dense and does so having both a palatable texture and a stable flavor delivery system.
It is apparent that a need exists for a flavor system which has good shelf life when used in conjunction with aspartame and/or high levels of protein.